Plastic drum closure



Nov. 27, 1956 RlEKE PLASTIC DRUM CLOSURE Filed Dec. 21, 1953 .F. M w r R v V, 0 m m Mr N. r 0U w fl z m m a I I I 4 United States Patent() PLASTIC DRUM CLOSURE Glenn T. Rieke, Auburn, Ind., assignor to Rieke Metal Products Corporation, Auburn, Iud., a corporation Application December 21, 1953, Serial No. 399,349

3 Claims. (Cl. 22027) This invention relates to a plastic drum closure for heavy duty steel drums and containers, and in particular those drums adapted for containing chemicals such as may contaminate or be contaminated by the conventional metal drums.

In the use of heavy duty steel drums or barrels for containing chemicals and such fluids which may be contaminated through contact with metal, it has become the practice to line such drums with a chemical impervious substance serving to protect both the chemical contents and the metal of the drum. It is therefore the purpose of this invention to provide a sealing closure for such a drum which will similarly be impervious to the action of the chemical. A suitable material for this purpose is polyethylene.

it is further desirable in the use of such heavy duty drums or barrels, particularly in respect to initially filling them, for the drum or barrel manufacturer to supply the user with said drum formed with a simple filler opening, and wherein after the drum has been filled, or cleaned after use and refilled, the user may conveniently clamp in place a closure unit including a bung ring and closure plug.

It is, therefore, the object of this invention to provide a suitable chemical proof closure bung ring and plug as a unit adapted to be readily clamped over the opening of the drum by the user, and which may be removed by the user for cleaning, refilling and replacement.

The particular feature of the invention resides in the closure unit comprising an internally threaded natural polyethylene bung ring so formed as to effect a tamperproof seal for the drum unit, and also a seal between the ring and the drum, on the one hand, and a sealing gasket portion for a plug or the like, on the other hand. Said unit may further include an externally threaded removable plug member or the like formed to be screwed into the ring in sealing engagement with its sealing gasket portion, and a clamping ring for readily clamping and sealing the bung ring to the drum. Said clamping ring may if so desired be provided with a tearofi tab by which it may be readily removed for cleaning and refilling the drum. Additionally the opening of the drum may be serrated as well as the bung ring for interengagement to resist relative rotation therebetween upon screwing a plug or the like into and out of sealing relation with the flange.

The advantages of such an arrangement reside in the larger opening for filling the drum by the user with the entire closure unit, including the bung ring, removed.

A particular advantage resides in the formation of the sealing gasket portion comprising the bung ring itself for sealing engagement by a plug or the like which eliminates the cost and inconvenience of providing a ICC separate plug gasket of the usual character. Furthermore, hermetic and tamper-proof cap seals as usually employed, are unnecessary because of the cutout diaphragm formed in the bottom of the bung ring which provides a tamper-proof seal during shipment and storage, but which can readily be removed when the drum is placed in use. p

A further advantage of the closure in this invention resides in the unitary structure of the bung ring, plug, clamping ring and plug gasket, such as may be readily applied and removed as a unit by the user. Wherein the ring, including its hermetic tamper-proof diaphragm, is formed of a suitable chemical impervious substance, such as natural polyethylene, it is free from attack by the contents during storage and shipment and is therefore ideal for lined containers. When the drum has been emptied the entire closure unit may be readily removed through the medium of the tearoir tab extending outwardly from the retaining ring. The drum may therefore be readily cleaned in the reconditioning plant and after being refilled a new closure unit may be clamped in place. Thus, the container may be reused many times. It may further be noted that any conventional dispensing equipment, such as faucets, molygates or pumps may be threaded into the ring in place of the closure plug.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

Fig. 1 is an exploded view of the closure unit including the bung ring with its sealing and gasket structure, the clamping ring and the screw plug thereof, each of said parts being shown in central vertical section.

Fig. 2 is a central vertical section through the assembly closure unit positioned for seating and clamping upon the drum.

Fig. 3 is a central vertical section through a portion of the drum with the closure unit clamped thereto.

Fig. 4 is a plan view of the underside of the closure unit taken on the line 4-4 of Fig. 2.

Fig. 5 is a plan view looking down on the opening of the drum taken on the line 5-5 of Fig. 2.

In the drawings there is shown a heavy duty metal drum or barrel 10 provided with the usual top plate 11 having an annular filler opening 12. The filler opening is surrounded by a collar 13 expanding upwardly from the top plate 11 to provide a Z-shaped undercut terminating in an inwardly extending sealing ledge 14. The sealing ledge is formed with a series of toothed serrations, as indicated at 15 in Fig. 5, formed about the inner periphery thereof.

The sealing unit, as shown in Fig. 1, includes a bung ring 16 formed of a suitable chemical impervious material, such as natural polyethylene, and which material is inherently compressible to provide a suitable sealing gasket. Said bung ring is cup-shaped in form, being internally threaded at 17 and having an open beveled top 18 and a hermetic and tamper-proof diaphragm 19 forming the bottom closed end thereof. Said diaphragm is surrounded by an annular cutout ring 20 lying adjacent the surrounding vertical wall. Said cutout ring is of substantially reduced thickness to provide for ready severance of the diaphragm from the body ofthebung ring when the contents of the drum are to be dispensed. Said flange member is further formed with an outwardly extending sealing lip portion 21 terminating in a downwardly extending portion 22. At spaced intervals about Patented Nov. 27, 1956 Fig. 3.

the body or wall of the bung ring there is a series of serrations or tooth-like projections 23. Extending upwardly above the sealing lip portion 21 and in upward continuation of the body or wall of the bung ring there is formed integral therewith a sealing gasket 24.

Also, as shown in Fig. 1, said closure unit is provided with a clamping ring 25 of suitable metal to be crimped into clamping position by a suitable tool about the periphery thereof. Said clamping ring includes an inwardly extending sealing flange portion 26 terminating inwardly in an upwardly curved annular lip portion 27. Said clamping ring is also provided with a tearoif tab 28, as shown in Fig. 4, for the purpose hereinafter moved. The contents may then be dispensed, subject to temporary closure if desired, by again applying the plug;

described. Said clamping ring is adapted to seat over to nest within the cup-shaped bung ring 16 and is provided externally with screw threads 30 for threaded engagement with the threads 17 of said bung ring. The

lower portion of the plug is closed by a closure plate 31. The body or wall of the plug terminates at the open end in an outwardly extending sealing lip 32. Externally of the plug there may be formed or secured an upstanding tool gripping projection indicated at 33.

The closure unit, including the above described structural elements thereof, asshown in Fig. 1, is assembled for use in the manner shown in Fig. 2. The heavy duty drum or similar container is provided to the user in the form shown at the bottom of Fig. 2 for filling or cleansing For reuse of the drum, the plug or the like may be removed and the .tearoff tab gripped to unseat the clamping ring from about the bung ring which will permit the bung ring to be readily removed from about the collar of the drum. However, for this purpose the tearoif tab may be dispensed with, in which event the clamping ring may be removed by a suitable tool. The drum is then in its original condition 'as to its opening for cleansing and refilling. After refilling 'a new. closure unit may be applied as above described, which unit need, if desired, ac quire only a new bung ring and clamping ring with the used plug mounted therein. Wherein the bung ring is shown and described herein asreceiving a plug indicated.

at 29, such plug may comprise or be in the forni' of any removable closure for the bung ring including dispensing equipment such as faucets, pumps or molyga tes, as Well known and practiced in the art.

The invention claimed is:

l. A closure unit for containers having an annular opening surrounded by an upstanding collar terminating in an inwardly extending ledge, comprising a cup-shaped internally threaded bung ring open at the top and initially closed at the bottom by a severable diaphragm, said ring being composed of a compressible and resilient chemical impervious material, a lip portion formed on said ring of the same material to extend radially outwardly therefrom and refilling with the closure unit removed. After filling cut of the'collar to secure the unit in place. Such clamping compressesv the resilient material of the bung ring to effect a seal between the downwardly extending portion 22 of the sealing lip portion and the periphery of the collar 13. The undercut of the collar also causes the sealing flange portion 26 of the clamping ring to be drawn 'down to compress the outwardly extending portion of the sealing lip against the sealing ledge 14 of the collar. Thus, the unit is secured firmly in sealing and locking engagement with the drum, as shown in In this position it will be observed that all inwardly exposed surfaces of the, closure are of chemical impervious material, as may also be applied to the in terior of the drum by the manufacturer thereof.

Where desired, and to interlock the closure with the drum to prevent angular displacement, the drum .and flange may be provided with the interlocking multi-sided formation, such as theserrations or teeth 15, 23, as shown in Figs. 4 and 5..

e .As above described, in. assembling the flange unit of Fig. 2, the plug may be screwed home in the flange until its sealing lip 32 is in compressing and sealing engagement with the upstanding sealing gasket portion' 24 of the resilient material. Thus, it is not necessary to provide a separate and independent gasket between'the plug and the bung ring as is usually employed.

By reason of the integral diaphragm 19 formed atthe bottom of the bung ring as an integral part thereof, the

closure provides a hermetic and tamper-proof seal which eliminates theusual requirement of cap seals and the like. Such diaphragm remains in place during shipment and storage of the drum with its contents; However, when it is desired to use the contents of'the drum, the plug is'unscrewed and removed from the bung ring, ex

'posing the diaphragm 19 and its cutout ring 20. By applying a knife the diaphragm may thereupon be severed from the body portion of the bung ring and reed to snugly seat on said ledge and envelop said. collar, an upwardly extending sealing gasket portion formed on said ring of the same material to extend upwardly from said lip portion, a clamping ring including 'an annular; wall and sealing flange portion conforming to and snugly embracing said lip portion for securely clamping said lip portion to and in sealing relation with said collar, and an externally threaded plug removably mounted in said bung 7 ring having an outwardly extending sealing lip engageable with said sealing gasket portion.

2. A closure unit for containers having'an annular opening surrounded by an upstanding collar terminating ural polyethylene or like material, an annular inverted cup-like lip portion integral with the outer periphery of, said ring to extend radially outwardly therefrom adapted to snugly seat on said ledge and envelop saidcolla'r, said ring and lip portion being formed with a mating multisided formation conforming to. and interlocking with the formation of said ledge for preventing angular displacement of said bung ring, an upstanding sealing gasket portion of the same material formed on said ring to ex-' tend upwardly from said lip portion, a clamping ring including an annular wall and sealing flange portion con forming to and snugly embracing said lip portion for securely clamping said lip portion to and in sealing relation with said collar, a tearoff tab extending radially out wardly from said clamping ring for facilitating forcible removal of said clamping ring from clamping engage' ment with said bung ring to permitremoval thereof from said container for use,-fand an externally threaded plug removably mounted on said bung ring having an outward 1y extending sealing lip engagement with said sealing gasket portion.

3. A closure unit comprising a cup-shaped internally threaded bung ring composed of naturalpolyethylene or like material, said ring being open at the top and initially closed at the bottom by a severable diaphragm, a lip porextend upwardly from said lip portion, a clamping ring 5 including an annular wall and sealing flange portion conforming to and snugly embracing said lip portion, and an externally threaded plug removably mounted in said bung ring having an outwardly extending sealing lip engageable with said sealing gasket portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,574,690 Radabaugh Feb. 23, 1926 6 Behringer Nov. 8, 1932 11g Mar. 28, 1939 Hanraham Feb. 20, 1945 Rieke Aug. 28, 1951 FOREIGN PATENTS France Sept. 4, 1933 Belgium Feb. 28, 1953 

